cf7537ea5f
The code in the Tendermint repository makes heavy use of import aliasing. This is made necessary by our extensive reuse of common base package names, and by repetition of similar names across different subdirectories. Unfortunately we have not been very consistent about which packages we alias in various circumstances, and the aliases we use vary. In the spirit of the advice in the style guide and https://github.com/golang/go/wiki/CodeReviewComments#imports, his change makes an effort to clean up and normalize import aliasing. This change makes no API or behavioral changes. It is a pure cleanup intended o help make the code more readable to developers (including myself) trying to understand what is being imported where. Only unexported names have been modified, and the changes were generated and applied mechanically with gofmt -r and comby, respecting the lexical and syntactic rules of Go. Even so, I did not fix every inconsistency. Where the changes would be too disruptive, I left it alone. The principles I followed in this cleanup are: - Remove aliases that restate the package name. - Remove aliases where the base package name is unambiguous. - Move overly-terse abbreviations from the import to the usage site. - Fix lexical issues (remove underscores, remove capitalization). - Fix import groupings to more closely match the style guide. - Group blank (side-effecting) imports and ensure they are commented. - Add aliases to multiple imports with the same base package name.
KVStore
There are two app's here: the KVStoreApplication and the PersistentKVStoreApplication.
KVStoreApplication
The KVStoreApplication is a simple merkle key-value store.
Transactions of the form key=value are stored as key-value pairs in the tree.
Transactions without an = sign set the value to the key.
The app has no replay protection (other than what the mempool provides).
PersistentKVStoreApplication
The PersistentKVStoreApplication wraps the KVStoreApplication and provides two additional features:
- persistence of state across app restarts (using Tendermint's ABCI-Handshake mechanism)
- validator set changes
The state is persisted in leveldb along with the last block committed, and the Handshake allows any necessary blocks to be replayed. Validator set changes are effected using the following transaction format:
"val:pubkey1!power1,pubkey2!power2,pubkey3!power3"
where pubkeyN is a base64-encoded 32-byte ed25519 key and powerN is a new voting power for the validator with pubkeyN (possibly a new one).
To remove a validator from the validator set, set power to 0.
There is no sybil protection against new validators joining.